Structural insights and molecular advancements in fluorene-based electroluminescent materials: A mini-review

• Fluorene derivatives provide efficient, stable optoelectronic properties. • Improved polyfluorene synthesis boosts luminescence and durability. • Stable blue light emission is vital for OLED technologies. • Copolymerization enhances fluorene's emission and stability features. • Spiro structures significantly improve thermal and spectral performance. Organic electroluminescent materials have emerged as pivotal components within the optoelectronic sector, offering distinct advantages over their inorganic counterparts and smaller organic molecules. Their extensive availability, ease of processing, and the versatility in tuning luminescent properties through molecular design render these polymers highly suitable for advanced display technologies. Among these materials, fluorene derivatives are particularly noteworthy due to their rigid planar biphenyl structures, wide bandgaps, and high luminous efficiencies, positioning them as leading candidates in the quest for superior electroluminescent applications. This review elucidates recent advancements in the development of fluorene-based electroluminescent materials. It delves into the nuances of various fluorene configurations, including small molecular structures, homopolymers, copolymers, branched variants, and specifically, polyfluorenes with innovative spiro modifications at the C-9 position. Through this analysis, we highlight how each configuration contributes to the evolving landscape of electroluminescent technologies, underscoring the significant potential of fluorene-based materials in shaping future optoelectronic applications.